Telephone-transmitter.



'No. 759,441. PATENTED MAY 10, 1904.

i A. W. HILL.

TELEPHONE TRANSMITTER. APPLIOATION TILED 001.9. 1902.

N0 MODEL.

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UNITED STATES Patented May 10, 1904.

PATENT OEEIeE.

ALFRED W. HILL, OF WEST HOBOKEN, NEW JERSEY, ASSIGNOR TO HIM- SELF, AND D. I. CHESEBRO AND ALFRED E. DAVIDSON, OF N EIV YORK, N; Y., DOING BUSINESS AS PHONIO CARBON COMPANY.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent N0.759,441, dated May 10, 1904.

Application filed October 9, 1902.

To all whom it may concern.-

Be it known that I, ALFRED W. HILL, a citizen of the United States, and a resident of l/Vest Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Telephone- Transmitters, of which the following is a speci fication.

My invention relates to that class of telephone transmitters known as solidback transmitters.

The object .of my invention is to simplify and cheapen the construction of transmitters of this class. i

My invention is especially useful for telephone-transmitters in which a mass of granular material is interposed between the electrodes supported, respectively, by the solid back and by the diaphragm, although it may be employed with telephone-transmitters having other forms or constructions of electrodes for varying the electric current.

My invention consists in the solid carbon disk or block formed as hereinafter described and adapted to constitute an electrode of the instrument as well as the solid back thereof, and at the same time to afford means for properly supporting and retaining the parts of the instrument in their desired relation, all as" hereinafter set forth and claimed. The solid disk or block may be made from any suitable carbon composition and consolidated under pressure in the way commonly employed to make up the thin carbon disks or wafers mounted in and operating as the electrode of previous constructions of telephonetransmitter, or it may be otherwise formed or made of other kinds of carbon, so that it shall serve as anelectrode of the instrument.

Figure 1 of the accompanying drawings is a transverse section through an instrument provided with the solid .carbon disk and back forming my invention. Fig. 2 is a plan of Serial No. 126,371. (No modeL) the diaphragm and for the mass of carbon held in the cavity at the center of the carbon disk or block and resting upon the floor of said cavity, which thereby constitutes an electrode of the instrument. Fig. 3 is an enlarged section through the central portion of the disk and the parts associated therewith.

1 indicates the solid disk or block of carbon constituting the transmitter back and electrode, and 2 indicates the front of the instrument, which may be made of metal or other desired material and is bolted directly upon an annular seat or ledge at the outer edge of the disk or block. The inner edge of this annular ledge or seat is indicated by the circular line 5, Fig. 2, between which and the outer edge of the disk are shown on the same diametrical line two bolt holes or openings which are employed for fastening the front down upon the said annular seat. The front piece carries, as usual, a mouthpiece 3. Within the annular shoulder 5 is an annular depression or ledge on the face of the disk adapted to receive and afford a rest for the annular edge of the diaphragm 4: of the instrument, which diaphragm is properly separated at said annular edge from the material of the block 1, and from the inner face of the front piece by suitable elastic washers whereby it is allowed suitable freedom of movement at its edge and also insulated from the carbon disk and preferably from the metal front. The inner edge of the annular rest for the edge of the diaphragm is indicated by the circular line 6, Fig. 2, which shows the location of the upper edge or shoulder of another an nular depression whose inner edge is marked by the circular line 7. Said annulardepression alfords a free airspace back of the diaphragm, so that the vibrations of the central portion shall not be confined.

At the center of the block 1 is provided a cavity which holds the granular material 8. The upper annular edge or shoulder of this cavity is marked 7 in the plan Fig. 2. Said granular material, which may be of carbon, is sustained directly upon the wall or floor of this cavity in the block 1, and said wall or floor takes the place of the disk of carbon fastened to a metal disk sustained in a suitable back piece in the manner employed in one of the constructions of instrument heretofore in common use.

9 is the opposite electrode or disk of carbon fastened in the usual way to a metal disk 10, forming an expanded end of a bolt or pin 11, which is bolted to the diaphragm in the usual manner and which is provided with a metal washer 12, between which and the expanded disk or bolt 9 is interposed, as usual in the art, a felt or other elastic disk 13.

Connection with carbon disk or button 9 is made through the metal washer 12, which is electrically connected with the stud or plate l1 and is provided with a connection running to a screw post or terminal 14, setting in an opening in the back of the block 1, but insulated therefrom by a proper bushing of hard rubber or other material 15. v

The granular material 8 is kept out of contact with the sides of the cavity in which it is supported by means of the sleeve 16, of insulating material, as shown, which operates to force the current to take the path from the carbon disk or button 9 through the granu; lar material to the opposite electrode, against which it is compressed, and which consists of the floor or portion of the floor of the cavity formed in the face of the carbon block 1. Electrical connection to such back electrode may be made by attachment to the bolts fastening the front and back of the instrument together or to any other portion of the metal work which is in electrical connection with the carbon back.

The instrument as described may be fastened to the usual support 17 by a screw or otherwise, as well understood in the art.

What I claim as my invention isl. The hereinbefore-described solid disk of carbon constituting an electrode and back for a telephone-transmitter and having as described an annular ledge or rest adapted to support the diaphragm of the instrument at its edge and a central depression or cavity inclosed at the rear face of the disk and adapted to hold granular material.

2. The hereinbefore-described solid disk of carbon. adapted to form a back and electrode for a telephone-transmitter and provided with annular ledges adapted to support the front of the instrument and the diaphragm respectively, and with an interior annular depression to form an air-space back of the diaphragm and with a central cavity or depression adapted to hold the granular material and to form by its floor or bottom one of the electrodes of the instrument.

8. As a new article of manufacture, a solid disk of carbon adapted to form the back and electrode of a telephone-transmitter and having concentric annular rests or depressions, as and for the purpose described.

4:. In a telephone-transmitter, a solid block of carbon having an annular seat or projection on one face at its edge, a concentric annular depression within said seat the floor of which depression affords a rest for the diaphragm of the instrument, a depression in the face of said disk forming a sound-cavity or air-space back of said diaphragm and having an annular boundary formed by the rest for the edge of the diaphragm, and a granule-receiving depression at the center the floor of which depression lies below the level of said air-space and forms as described one of the electrodes ofthe instrument.

5. The combination substantially as described of the solid block of carbon 1, a diaphragm resting upon an annular seat or ledge in the face of said disk or block, said block having a central depression or cavity the floor of which forms an electrode of the instrument, granular material confined within said depression, a disk of carbon 9 fastened to and vibrating with the diaphragm and adapted to rest upon the granular material and a confining-sleeve 16 of insulating material.

6. The combination substantially as described, of a solid block or disk of carbon 1 having an annular rest or ledge and a central cavity or .depression whose floor forms an electrode of the instrument, a front piece bolted directly to one face of said disk, a diaphragm secured over a sound-cavity in one face of said disk and resting upon said annular rest or ledge, a support 17, and means for securing the said carbon disk directly to said Support.

7. As an article of manufacture, a disk of carbon formed as described to adapt it to constitute at one and the same time a continuous solid back for a telephone-transmitter and the back electrode upon which the granular material of the instrument impinges and also to afiord at or near its edge an annular support or rest for the diaphragm of the instrument.

Signed at New York, in the county of New York and State of New York, this 1st day of October, A. D. 1902.

ALFRED W. HILL.

Witnesses:

J. GALLwrrz, E. L. LAWLER. 

